The present disclosure relates to fixing devices and image forming apparatuses.
Electrographic image forming apparatuses include a fixing device that fixes a toner image to a sheet by applying heat and pressure. The fixing device of such an image forming apparatus is provided with a cam to change the pressure according to the thickness of a sheet to which a toner image is to be fixed. To print on a sheet of which part is thick, such as an envelope, the pressure is reduced when compared with that applied to plain paper, thereby reducing production of wrinkles in the sheet.